Initial Thoughts:
Well so far it's installed into my server (Windows Server 2008 R2) on a Maximus Formula (X38). Initially, it axed the Intel RAID and the motherboard was unable to boot from any of the drives attached to the ICH9R. In my scenario, I did not want to boot from the RAID card, so I had no need for the BIOS to detect it. Luckily when you go into the configuration just after POST, there's an option that lets you disable the card entirely, or enable only in OS, BIOS or both. As such, I chose the OS option which allowed me to regain my ICH9R boot support.

Honestly, I have no idea how much offloading this does. Looks like it means business with the heatsink on it, but who knows. At $180 I'm not expecting too much. The fact that it lacks RAID5 leads me to think that it probably doesn't do much logic. Mainly just needed the extra ports, and didn't want some piece of garbage Silicon Image controller. No harm in having SATA 6Gbps support either.

Software/Firmware:
Firmware and BIOS updating was effortless. Can do it from within Windows or DOS. Pretty much the same as flashing a motherboard BIOS. Only difference here is that the BIOS and Firmware are separate and the firmware has two editions: IR and IT. IR stands for Integrated RAID and probably the option you'd typically want. IT is for Initiator which I'm not quite sure what that's for.

On the software side, it has this MegaRAID Storage Mananger application which allows you to mange anything you could possibly want really. Create arrays, check their status, etc. A little more advanced than Intel Rapid Storage Technology of course, but still fairly simple to use.

Windows was able to find and install drivers for it automatically which is always good. Means that installing the OS onto it should be effortless. LSI does offer driver downloads as well which I decided to install.

Performance:
I'm running 2x Seagate 7200.12 1TB (CC46 firmware) and 2x Samsung F3 1TB in RAID10 on this card. Maybe not the most ideal setup, but I opted to mix the drives to lessen the chance of it all failing at once. One of each drive were bought a few months ago, with the other two bought last week.

Running 4x1TB in RAID10 results in approximately 1.8TB of usable space. It offers the best of both worlds in theory, as you basically have a RAID0 of two RAID1 arrays. It also shouldn't suffer from major slowness when in a degraded state should one drive fail compared to RAID5. And with the price of HDDs dropping rapidly, why not get 4 drives instead of 3?

After creating the RAID10 array, it then needs to initialize. This process seems to be rather time consuming and is still in progress. I started around 7PM, and it's now 12PM and I'm at 23%. During this time, the array is not visible to Windows, so you cannot start using it.

Very interesting, im looking forward to your benchmarks for some comparisons! I've recently gotten a Dell Perc 6i for my file server and have set up a 4x 7200.12 1Tb Raid 10 array as well. I'd be very interested to see how the two controllers handle similar arrays. Are you installing windows on the array or a separate drive? What cluster size are you using? Read through? Write back? Let me know and ill follow suit for the most accurate comparisons

Read through/write back? Not sure, but I'm guessing not as I don't see them listed anywhere. I've attached all the information though from the MegaRAID program. If you can point me to where I can enable them, I might consider. I do have a UPS on my server now...

Any thoughts on how to get the Intel RAID + LSI RAID to co-operate? Seems the LSI one just takes over and then the Intel RAID is gone...

The way I thought it would of worked doesn't seem like it will. Array isn't found in Windows, but before I built the array, the single drives showed.

Seems to be a fairly typical problem on consumer-grade motherboards. Guess I should of looked into things more... Worse comes to worse, I'll use it in my PC since it seems to work fine with Intel AHCI. And then get an 8-port card for my server.

I completely forgot about this thread (sorry about that ) but there in your post you can see that you have No read ahead but Write through is disabled.

Im trying out the WHS "Vail" trial right now, with the OS running off of a partition on the array.

Jdrom, could you post ATTO benches please? I dont use crystaldiskmark, although i suppose i could try it if you think its better than ATTO. I just prefer the atto one because it shows you read and writes speeds for many many files sizes from 4k up. Thanks dude!